Respuesta :

jeremiahkevinm

Answer:

-x² - 10x -21 = 0

x² +10x +21 = 0

x² + 7x + 3x + 21 = 0

x ( x+7) + 3 (x+7) = 0

(x+3) (x+7) = 0

when (x+3) = 0,

   x = -3

Again,

(x+7) = 0

x = -7

Answer:

7 and 3

Step-by-step explanation:

-b +/- sqrt(b^2+4ac)/2a

10 +/- sqrt(100-84)/2

10 +/- 4/2

7 and 3